(1) Field of the Invention
The present invention relates generally to Cartesian robots used in conjunction with an automated clinical laboratory conveyor system, and more particularly to an improved two-axis robot for transferring specimen tubes from one location to another.
(2) Background Information
Clinical laboratory testing has changed and improved remarkably over the past 80 years. Initially, tests or assays were performed manually and generally utilized large quantities of serum, blood or other materials and/or body fluids. As mechanical technology developed in the industrial work place, similar technology was introduced into the clinical laboratory. With the introduction of new technology, methodologies were also improved in an effort to improve the quality of the results produced by the individual instruments, and to minimize the amount of physical specimen required to perform a particular test.
Instruments have been developed to increase the efficiency of testing procedures by reducing turnaround time and decreasing the volumes necessary to perform various assays. Robotic engineering has evolved to such a degree that various types of robots have been applied in the clinical laboratory setting.
The main focus of prior art laboratory automation relied on the implementation of conveyor systems to connect areas of a clinical laboratory. Known conveyor systems in the laboratory setting utilize separate conveyor segments to move specimens from a processing station to a specific laboratory work station. In order to obtain cost savings, one typical scenario called for specimens to be sorted manually and grouped together in a carrier rack to be conveyed to a specific location. In this way, a carrier would move a group of 5-20 specimens from the processing location to the specific work station for the performance of a single test on each of the specimens within the carrier rack.
With the development of new and improved automatic conveyor systems for laboratories and other environments, it is possible to select, track, and convey individual specimens throughout a laboratory for a variety of different testing, while maintaining a priority system for certain types of testing or special urgent requests for a time-specific response. These new automated conveyor systems are of various types and design, but the inventors herein have found that a dual conveyor system, using a pair of parallel conveyor tracks circulating throughout a laboratory, provides the greatest flexibility and versatility. The integration of various track devices with software directing the operation of the conveyor system and the various automated testing stations, has improved both the speed and capability of automated conveyor systems in recent years.
Track devices form the physical interface between the specimen samples in carriers being directed throughout the system, while the Laboratory Automation System (LAS) database provides direction for the system through its command and control features. The LAS and the various track devices work in combination to direct, manage and track all specimens throughout the system.
With the development of robotics to assist in the laboratory setting, the three-axis Cartesian robot has been the conventional device installed to load and unload specimen tubes in specimen carriers. These three-axis robots identify the X and Y coordinates of the specimen tube location in a carrier and then grip the tube and raise and lower the tube into the carrier, along the Z axis.
While Cartesian robots are adequate to perform this task, in the case of a carrier located at a predetermined position along a straight conveyor track, the need for the expensive Cartesian robot is less necessary. The inventors herein have found that a simple two-axis robot can perform the identical function, at a reduced initial cost, and with the attendant lower costs of maintenance and repair of a less complicated device.